Automatic wiper apparatus

Abstract

Abstract PURPOSE:To prevent a wiper blade from mulfunction by renew setting a reference signal value on the basis of the signal value detected by a raindrop sensor when the wiper blade wipes and passes by a portion of a window glass to be detected. CONSTITUTION:When raindrops attach to a portion of a window glass to be detected, the signal value detected by an optical raindrop sensor 2 becomes lower than the reference signal value of a reference value attaching circuit 9 so that a comparing circuit 4 applies the trigger signal output to a wiper drive section 5. Thus a wiper motor rotates so that a wiper blade wipes once. The signal value detected by the sensor 2 immediately after wiping is held in a sample holding circuit 8 and the reference signal of the sample value minus a certain value is supplied from the reference value attaching circuit 9 to the comparing circuit 4. This reference signal value is little affected by raindrops but only by environment and temperature in which the wiper is used. Thus, the wiper blade is not subjected to mulfunction by change in the environment or the like under which the sensor 2 is used.

Inventors

• 👤 Masahiro Adachi
• 👤 正博 足立

Bibliographic Details